Coating composition



Patented May 30, 1944 COATING COMPOSITION Johan Marius Hoefielman, Amsterdam, Netherlands, assignor to Shell Development Company, San Francisco, Calif., a corporation of Dela-" ware No Drawing. Application November 1, 19 Serial No. 363,911. In France June 29, 1939 11- Claims. (Cl. 106285) This invention relates to a process for the manufacture of oils having improved wetting and adhesion powers toward solids in the presence of moisture, and is more particularly concerned with substantially asphalt-free mineral oils that have been treated with sulfate or sulfonate esters.

It is a purpose of this invention to provide an oil of improved adhesion power toward solid surfaces, which oil is not readily displaced therefrom by water. It is another purpose to improve corrosion protective properties of lubricating and similar oils. Still another purpose is to provide a coating oil for mineral aggregates capable of strengthening the adhesive bond of asphalts with the aggregate. Other advantages and purposes present themselves .from the description below.

I have discovered that the wetting power of substantially asphalt-free oils for metals, mineral aggregates, fibrous materials, pigments or othersolid surfaces can be improved by treating the oils at elevated temperatures with an ester of a sulfuric or sulfonic acid. The treatment is particularly applicable to normally liquid asphaltfree mineral oils, which, during their conventional use, remain in the liquid state, i. e., which need not be vaporized in the course of their normal application, such as lubricating oils, gas oil, kerosene, steam. refined paraflinic oils, and particularly unrefined or partially refined petroleum distillates as well as extracts, etc., as well as to fatty oils or mixtures of fattyoils with one or several of the above mineral oils.

The process according to the present invention comprises treating suitable oils which are substantially free from asphalt, or compositions containing such mineral oils with small quantities of an ester combining sulfuric acid or an aryl sulfonic acid with a lower primary aliphatic alcohol, or substances capable of yielding these esters. Such substances can be represented by the formula in which R is a primary alkyl group and X is a hydroxyl group or a primary alkoxy or aryl radical. These are referred to as sulfo compounds in the appended claims. By lower alcohols are meant those alcohols having not more than 8 carbon atoms.

results.

An example of a mixture of substances which may yield a suitable primary alcohol ester is amixture of methyl alcohol and sulfuric acid.

The ester or other mixtures capable of yielding the esters may be added as such or in solution of suitable solvents. The amount of esters required to achieve the desired treatment is between about 2% t 5%, although larger, amounts may be em- Examples of suitable esters are: dimethyl sulfate, methyl ethyl sulfate, diethyl sulfate, di-npropyl sulfate, diisopropyl sulfate, dibutyi sulfates, diamyl sulfates, methyl acid sulfate, ethyl. acid ployed.

The treatment of the oil is advantageously carried out at a temperature between about 50-200 C., a preferred temperature range of treatment being'between about -120 C. Under these conditions a reaction takes place between the ester and the oil.

The time of heat treating required to attain the desired efiect depends largely on the treating temperature, the minimum time required being approximatelyinversely proportional to the temperature. Treatment at 50 C. may require at least an hour, while at a temperature of about C. a. few minutes may be sufficient. at 200 C. a contact time ofnot more than about one minute is necessary. The treating time and temperaure may also depend to some extent on the nature of the ester and of the treating stock. If desired, compounds inert to the action of the ester may be added to the mineral oil before or after the treatment.

Mineral oils and mineral oil compositions treated according to my invention may be employed for various purposes. While the oils treated are endowed with improved powers of wetting and adhesion for granite, quartz, limestone and wood,

it is particularly toward metals that these powers are enhanced. Thus the oils possess exceptional utility in the lubrication of the tracks of tractors. gears, racks, shafts, worms, chains, cranks and other mechanical parts of machines that are exposed to the atmosphere. I

The following examples serve to illustrate my invention:

Example I A Venezuelan raw lubricating distillate free from asphalt, Eso='l0, was treated for twenty minutes at 110 C. with by weight of dimethyl sulfate. The oil so produced effectively protected iron against the corrosive action of dilute sulfuric acid, as measured by the fermm reductum test,

described in Petroleum, No. 49, 1935, pages 4-8. In this same test, an untreated portion of the same distillate oil gave hardly any protection to the iron.

' In contrast to the above, a highly refined lubricating oil'obtained by extraction with 300 vol-" uxnes of furiural at 70 0., followed by acid and.

clay treatment, was only little improved by treatment withdimethyl sulfate.-

Example,

the "coating remained unchanged. A similar Edelean'u .extract oil which was not treated gave an inco'mpletecoating to the gravel and when it was. immersed into 'water. the oil coating almost immediately. withdrew and was displaced by the water. 7

Example Ill A lubricating Oil distillate Eso-c.=7 having a sulphur 'content of 0.8% was treated for minutes at 110 C. with 1% by weight dimethyl sulfate. The oil obtained was used to coat wet gran- 1 ite gravel, the quantity used being 1% by weight of the gravel. The resulting oily aggregate was afterwards easily and completely coated with 5% by weight of bituminous asphalt cut back with 15% kerosene in the conventional manner employed in road construction. When pretreating the same granite with the untreated oil the cut 4 back asphalt covered the aggregate poorly and incompletely.

I claim as my invention:

1. The process of improving the wetting properties of a substantially asphalt-free mineral lubricating oil comprising treating said oil with between about .2 and 5% by weight of a suite compound having the formula in which R is a primary alkyl group having up to.8 carbon atoms and! is an organic radical of the class consisting of hydrogcyl, primary alkoxy and aryl radicals, at a temperature between said oil and compound to form a reaction product remaining in said oil.

2. The process ofclaim' 1 in which the oil is treated with the sulfo compound at a temperature between 80 C. and 120 C.

3. The process of claim 1 in which the sulfo compound is a sulfuric acid ester of a lower primary alcohol.

4. The process of claim 1 in which the sulfo compound is an acid sulfuric acid ester of a lower primary alcohol. I

5. The process of claim 1 in which the sulfo compound is dimethyl sulfate.

u 6. The process of claim 1 in which the sulfo compound is an aryl sulfonic acid ester of a lower primary alcohol. 7.- The process of claim 1 in which the sulfo couipound is a methyl ester of a benzene sulfonic ac o -84Mi asphalt-free mineral lubricating oil of improved wetting power comprising the product of reaction of an asphalt-free minerallubricatot a sulfo compound of the formula ao-g-x in which R. is a primary alkyl group having up substantially asphalt-freemineral lubricating oil which has been reacted with between about 0.2% and 5% by weight of a suite compound having the formula 60 about C. and 200 0.. and for a time between in which R is a primary alkyl group having up to 8 carbon atoms and X is an organic radical of the class consisting of hydroxyl, primary alkoxy I and aryl radicals, at a temperature between about one hour andone minute, the time of contact being inversely proportional to the temperature of the treatment.

10. The surface covering of claim 9 in which the aggregates comprise porphy y gravel.

about 50 and 200 C. and for a time between about one hour and one minute, the time of contact being inversely proportional to the temperature of the treatment, to eliect a reaction between V 11. The siirface covering of claim 9 in which the aggregates comprise granite gravel.

JOHAN MARIUS HOEFFELMAN ing'oil with between about .2 and 5% by weight to 8 carbon atoms and X is an organic radical 

